Solenoid actuated valves have long been known in a wide variety of arts, especially in applications where valve activation timing and speed are important. One such application includes fuel injectors that utilize solenoid actuated control valves to control the timing and duration of injection events. Typically, these control valves have an internal valve member that is biased to one position between injection events, but is pulled to a second position by the solenoid during an injection event. In most cases, the solenoid is energized for a sufficient amount of time that the valve member comes to rest at its upper stop during the injection event. This is important because valve members often bounce one or more times when coming into contact with their upper stop shortly after the solenoid is energized. In the case of a relatively short injection event, the solenoid can sometimes be de-energized before the valve member has stabilized by coming to rest at its upper stop. When this occurs, the valve tends to behave somewhat erratically since the bouncing may cause the valve member to close faster such that less fuel is actually injected than was expected. This erratic behavior due to valve member bouncing is somewhat unpredictable and nonlinear since engineers have observed that it can vary from injector to injector and also vary from injection event to injection event for a fixed on-time in a single injector. Therefore, in order to achieve reliable and predictable performance, some correcting measures must be taken if the injector is to be operated in the brief on-time range where the bouncing phenomenon occurs.
The present invention is directed to these and other problems associated with valve member bouncing in solenoid actuated valves.